Question 1

What does the GPT-5 nano API cost?

Accepted Answer

The official OpenAI list price is $0.050 per 1M input tokens and $0.400 per 1M output tokens. Cached input is $0.005 per 1M tokens, 10× cheaper than the regular input.

Question 2

How much does 1 million tokens of GPT-5 nano cost?

Accepted Answer

1M input tokens cost $0.050, 1M output tokens — $0.400. With a 1:1 input/output load a million tokens works out to about $0.225. Chatbots with long context push the blended price down; code generation pushes it up.

Question 3

Where is the GPT-5 nano API cheapest?

Accepted Answer

There are no third-party quotes for this model yet. We parse price lists daily and the comparison appears here automatically.

Question 4

What is the GPT-5 nano context window?

Accepted Answer

The context window is 400K tokens. Some vendors raise the price above a context threshold — check the plan notes.

Question 5

How do I check that a provider key works?

Accepted Answer

The free checker sends a GET request to your endpoint's model list and reports status and latency. The key is not stored server-side.

GPT-5 nano API pricing: the official list and where to look next

What to check before buying